Separating finely-divided minerals



United States Patent 3,179,250 SEPARATHNG FEJELY-DIVIDED MWERALS Fred H. Bunge, Hibbing, Minn, and Robert E. Baarson, La Grange, and Harold B. Treweeir, Park Forest, 111., assignors to Armour and Company, Chicago, 111., a corporation of Delaware No Drawing. Filed July 31, 1961, Ser. No. 127,808

@laims. (Cl. 209-166) This invention relates to separating finely-divided minerals, and more particularly to a flotation process and flotation collectors for use in the separating of finelydivided minerals. The processes may be used advantageously in the concentration of iron ore by froth flotation and the separation of phosphate, potash, feldspar and other minerals.

An object of the invention is to provide an improved process for separating finely-divided minerals by froth flotation. A further object is to provide for the flotation process a new combination of flotation agents. Yet another object is to provide in a froth flotation process and in combination with a primary amine material, a flotation collector selected from the group consisting of ethoxylated fatty acids, amines, and amides, and propoxylated fatty acids, amines, and amides. A still further object is to provide in combination with a primary amine material flotation agent, an ethoxylatedor propoxylated collector which greatly increases the flotation strength and selectivity of the first collector. A still further object is to provide a novel combination of collectors having a synergistic effect in providing unusual strength and selectivity in the froth flotation separation process. Other specific objects and advantages will appear as the specification proceeds.

In one embodiment of our invention, we separate finelydivided minerals by froth flotation operation in which a water suspension of finely-divided minerals is conditioned with a primary amine and a flotation collector, which may be an ethoxylated fatty acid or amine or amide or a propoxylated fatty acid, amine or amide.

The primary amine component may be N-alkyl amine or N-alkyl propylene diamine, and the primary amine may be added together with the ethoxylated or propoxylated collector or the two collectors. may be added separately to the water suspension of finely-divided minerals.

The collectors may be added in the usual proportions employed for froth flotation in the separation of the finely-divided minerals, the proportions of the primary amine being preferably 66-99% and that of the ethoxylated or propoxylated collector being 341%. We prefer a range of 1-10% of the ethoxylated or propoxylated fatty acid, amine or amide and 99-90% of the primary amine collector.

The collectors are preferably added in the range of about 0.01-1 pound per ton of the ore on a dry weight basis, the preferred poundage being 0.05-0.3 pound per ton of the ore.

As a specific example, the water suspension of finelydivided minerals may be conditioned with N-alkyl amine, and there may be also, mixed with the watersuspension an ethoxylated amide, such as a hydrogenated tallow amide. The 2-3% ethoxylated amide added to a primary fatty acid amine flotation agent greatly improved the flotation strength (mineral collecting power) and selectivity of the primary amine reagent.

tailings from the Mesabi Iron Range in Minnesota.

3,179,250 Patented Apr. 20, 1965 ice As above stated, the flotation collector which is added to the primary amine may consist not only of an ethoxylated or propoxylated amide but also of ethoxylated or propoxylated fatty acids and amines. The fatty acids are derived from tallow, soya or coco origin and have from 8-18 carbon atoms. The amines are also preferably derived from fatty acids of this character.

As another specific example of the froth flotation process, the water suspension of finely-divided minerals was conditioned with a primary amine and an ethoxylated stearyl amine. In another example, the process em ployed, in place of the ethoxylated amine, ethoxylated red oil fatty acid.

In the separation of iron oxide minerals from siliceous gangue by froth flotation, the Water suspension of minerals was mixed with an amine acetate salt and an ethoxylated soya amine, and in this operation improved results were obtained in the flotation of the gangue from the iron oxide minerals.

We have discovered that the ethoxylated or propoxylated fatty acids, amines or amides can be very effectively used with a high molecular weight primary amine combined with nitrile pitch amine. The latter may consist of about one-third nitrile pitch amine and twothirds primary amine. i

The new collector comprises a primary fatty amine, or nitrile pitch amine,or mixtures thereof, in which from 2 to 3% of the total weight has been replaced with an alkoxylated fatty amide having the following structure 3)n 0 omb nbiln ll X Tomoaanoln 3) 11 wherein R is an aliphatic hydrocarbon group having from 12 to 22 carbon atoms, wherein a is an integer of from 0 to 1, wherein Z; is an integer of from 1 to 2, wherein when a is zero, b is 2, and when a is l, b is 1, wherein x+y is an integer of from 5 to 50.

Specific examples of the new processes may be set out as follows:

EXAMPLE I An ethoxylated amine, such as a soya amine, was incorporated with an amine acetate salt of distilled coco amine in the flotation of gangue from iron oxide minerals. The following tests were made on a sample of washer The sample of ore used for these tests cotnained 18.3% of mesh material. Preparation: The washer tailing ore was scrubbed and then deslimed after dispersing the slimes with 2.47 pounds per ton of Daxad 11 (a polymeri zed organic salt of sulphonic acid).

Reagents-pounds per ton (Corn Products Refining Co.)

. utes.

The process'was carried out as described in Example I with the following results:

Reagents-pounds per ton (Corn Products Refining Company) Gum Armac Ethomeen Frother Point of Addition 3502 CD S/12 DuPont First Float 1.0 0. 0375 0.0125 0.04 Second Float 0.0375 0.0125 0.04 Third Float 0.0375 0.0125 0.04

Metallurgical results Product Weight Assay Recovery Percent Percent Fe Percent Fe Slimes 35. 1 17. 95 29. 4 First Float 30. 2 1. 23 1. 9 Second FloaL- 9.4 3. 88 1. 9 Third. Float 1. 6 14. 93 0. 9 Concentrate 23. 7 59. 42 65. 9 Composite. 100. 21. 4 100.0

As indicated, the use of the Etho chemical resulted in a 4% increase in grade and 0.9% increase in Fe recovery.

EXAMPLE III The ore sample was a sample of amine circuit feed received from an industrial phosphate flotation plant. This material assayed 23.9% acid insoluble and 54.7% BPL (bone phosphate of 1ime)25.04% P 0 Ethoxylated hydrogenated tallow amide (Ethomid HT/ 15) was added to a mixture of 67.2% primary tallow amine and 32.8% nitrile pitch amine (Armoflote P) in the proportion of 3% of Ethomid and 97% Armoflote' P. In the flotation test, 650 g. "of wet ore as received was scrubbed for one minute with 2 lbs. H 50 per ton of ore at a pulp density of 30% solids. The scrubbed sample was then deslimed and washed once by decantation. The washed ore was then pulped to 16% solids with tap water. Following the addition of the above reagents consisting of the amines and ethoxylated amide, the ore was conditioned for A minute, followed by flotation for 1 /2 min- The scrubbing, conditioning, and flotation were conducted in a 500 g. Fagergren cell. The flotation pH ranged from 7.5 to 7.7. Kerosene auxiliary collector was employed in a constant 2:1 ratio by weight with the amine primary collector in the test. A constant 0.17 1b./ton of pine oil frother was used in each test. In comparison with the above tests, the procedure was carried through without the addition of the ethoxylated amide, and the results of the two tests compared. It was found that the addition of the ethoxylated product (Ethomid 'HT/ 15 to the Armoflote P substantially increased the selective rejection of acid insoluble gangue with resultant improved concentrate grade and phosphate recovery.

5%. The metallurgical results of the tests may be set out as follows:

The process Was carried out as described in Example Ill except that instead of using Ethornid HT/ 15 (hydrogenated tallow amide), there was substituted Ethomeen 18/60 (stearyl amine). The significant improvement by reason of the addition of the ethoxylated amine was obtained in the flotation strength and selectivity of the primary amine collector.

EXAMPLE V The process was carried out as described in Example III except that instead of the ethoxylated amide, there was employed Ethofat 142/20 (red oil type fatty acid).

Results substantially as described in Example IV were obtained.

While in the foregoing specification, we have set out the combinations of flotation collectors in considerable detail for the purpose of illustrating the invention, it will be understood that such deails may be varied widely by 0 those skilled in the art Without departing from the spirit of our invention.

We claim:

1. In a process for separating finely-divided minerals by froth flotation, the improvement comprising mixing directly with a water suspension of finely-divided minerals a flotation agent selected from the group consisting of primary amines, primary amine salts and mixtures thereof, and a flotation collector selected from the group consisting of ethoxylated fatty acids and amides and propoxylated fatty acids and amides, said flotation collector improving the flotation strength and selectivity of said flotation agent.

2.'The process of claim 1 in which the primary amine component is N-alkyl amine.

3. The process of claim 1 in which the primary amine component is N-alkyl propylene diamine.

4. The process of claim 1 in which the primary amine salt component is selected from the group consisting of primary amine acetate and primary amine hydrochloride.

collector is an ethoxylated fatty amide.

6. The process of claim 1 in which the said flotation collector is an ethoxylated fatty acid.

7. In a process for separating finely-divided minerals by froth flotation, the improvement comprising mixing directly with a water suspension of finely-divided minerals a primary amine and a nitrile pitch amine, said primary amine and said nitrile pitch amine being in the proportion of about 2 to 1, and an amide selected from the group consisting of ethoxylated and propoxylated amides.

8. In a process for separating iron oxide minerals from siliceous gangue by froth flotation, the improvement comprising mixing directly with a water suspension of said minerals and gangue an amine acetate and an ethoxylated amine, said ethoxylated amine improving the flotation strength and selectivity of the amine acetate.

9. In a process for separating phosphate minerals from siliceous gangue by froth flotation, the improvement com-' prising mixing directly with a water suspension of said minerals and gangue a flotation agent selected from the group consisting of primary amines, salts of primary amines and mixtures thereof, and a flotation collector selected from the group consisting of ethoxylatcd and propoxylated fatty amides.

10. The process of claim 9 in which the amide is ethoxylated hydrogenated tallow amide.

References Cited by the Examiner UNETED STATES PATENTS 2,298,281 10/42 Corley -1 209-466 2,816,870 12/57 Lentz 209166 2,914,174 11/59 Haseman 20=9166 6 FOREIGN PATENTS 3/40 Australia. 2/55 France. 10/ 5 8 Great Britain. 11/5 9 Germany.

8/ 60 France.

OTHER REFERENCES Etho-Chemicals, 1954, Armour Chemical Division.

GEGRGE D. MITCHELL, Primary Examiner.

HERBERT L. MARTIN, ROBERT L. OLEARY,

Examiners. 

1. IN A PROCESS FOR SEPARATING FINELY-DIVIDED MINERALS BY FROTH FLOTATION, THE IMPROVEMENT COMPRISING MIXING DIRECTLY WITH A WATER SUSPENSION OF FINELY-DIVIDED MINERALS A FLOTATION AGENT SELECTED FROM THE GROUP CONSISTING OF PRIMARY AMINES, PRIMARY AMINE SALTS AND MIXTURES THEREOF, AND A FLOTATION COLLECTOR SELECTED FROM THE GROUP CONSISTING OF ETHOXYLATED FATTY ACIDS AND AMIDES AND PROPOXYLATED FATTY ACIDS AND AMIDES, SAID FLOTATION COLLECTOR IMPROVING THE FLOTATION STRENGTH AND SELECTIVITY OF SAID FLOTATION AGENT. 